Guitar-like electronic musical instrument using resistor strips and potentiometer means to activate tone generators

ABSTRACT

An electronic guitar-like musical instrument comprises a central flat hollow box-like body with contoured forms extending laterally. A neck extends outwardly of one end of the body. On the neck is a fingerboard formed by a plurality of electrical resistance strips over which are suspended wire strings. On the box-like body is a control panel provided with controls for the instrument. A short fingerboard is also provided on the control panel and is formed by short electrical resistance strips over which are suspended other wire strings. Tone generators in the box-like body are electrically connected in circuit with the strings, resistance strips and controls on the panel. Potentiometers on the panel control separate tone generators. A vibrato bar extends outwardly of the body for varying pitch of generated tones. Picked notes and chords, sustained and continuously varied notes and chords can be generated by the instrument.

United States Patent 1191 Barkan 1 June 26, 1973 GUITAR-LIKE ELECTRONICMUSICAL INSTRUMENT USING RESISTOR STRIPS AND POTENTIOMETER MEANS TOACTIVATE TONE GENERATORS [21] Appl. No.: 165,213

[52] US. Cl 84/1.16, 84/l.17, 84/1.25 [51] Int. Cl. (31% 1/02, 61% 5/04[58] Field of Search 84/l.01, 1.16, 1.17, 84/1.24, 1.25, DIG. 30

[56] References Cited UNITED STATES PATENTS 2,070,344 2/1937 Waters84/DIG. 30 2,976,755 3/1961 Fender.. 84/1.16

3,147,332 9/1964 Fender 84/l.l6 X 3,493,669 2/1970 Elbrecht et al.84/l.l6 3,518,358 6/1970 Appleton 84/l.l6 X 3,524,375 8/1970 Hopping84/l.l6 X 3,662,641 5/1972 Allen et a1. 1 84/I.l6 X 3,673,304 6/1972Dudas 84/l.16 X

3,223,771 12/1965 Hopping 84/DIG. 30 3,482,028 12/1969 Cox et al.84/l.l6

3/1966 Rowe l/l97l Gasser Primary Examiner-Richard B. WilkinsonAssistant ExaminerStanley J. Witkowski Att0meyPolachek, Saulsbury &Hough [57] ABSTRACT An electronic guitar-like musical instrumentcomprises a central flat hollow box-like body with contoured formsextending laterally. A neck extends outwardly of one end of the body. Onthe neck is a fingerboard formed by a plurality of electrical resistancestrips over which are suspended wire strings. On the box-like body is acontrol panel provided with controls for the instrument. A shortfingerboard is also provided on the control panel and is formed by shortelectrical resistance strips over which are suspended other wirestrings. Tone generators in the box-like body are electrically connectedin circuit with the strings, resistance strips and controls on thepanel. Potentiometers on the panel control separate tone generators. Avibrato bar extends outwardly of the body for varying pitch of generatedtones. Picked notes and chords, sustained and continuously varied notesand chords can be generated by the instrument.

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GUITAR-LIKE ELECTRONIC MUSICAL INSTRUMENT USING RESISTOR STRIPS ANDPOTENTIOMETER MEANS TO ACTIVATE TONE GENERATORS This invention involvesan electronic musical instrument capable of playing electronicallygenerated musi cal tones in a manner familiar to a guitarist.

The instrument is electrically connected to an audio amplifier andloudspeaker system to produce audible music. According to the invention,the instrument has a hollow central box-like body containing componentsof electronic circuitry which controllably generate audio frequencytones. Extending laterally from the body are contoured forms used tosupport the body. The electronic circuitry has four sections. Anelongated neck secured to one of the forms carries a neck fingerboard.This fingerboard forms part of a first one of the circuit sections. Ithas six wire strings suspended over flat resistor strips each connectedin a circuit with its own audio frequency tone generator in the centralbody. By depressing any string against its resistor strip at any pointan electronic audio frequency signal is generated corresponding to theparticular string pressed and the point at which it contacts theresistance strip. By depressing the strings at marked pointscorresponding to the fret spacing of a conventional guitar, musicaltones are produced corresponding in pitch to those produced by a guitar.

Tones are produced analagous to picked tones by pressing a pick switchon the control panel. Picked chords can be produced by pressing two ormore-strings and simultaneously pressing a chord pick switch on thecontrol panel. A foot operated switch is provided for chord picking tofree the players hand which operates the pick switches for otheroperations. A bypass switch on the control panel permits production ofpicked or continuous tones with one hand alone, freeing the playersother hand to perform other operations. Tone and volume controls areprovided on the control panel of the central body for the neckfingerboards.

A second section includes a small fingerboard on the control panel ofthe central body. This body fingerboard has four suspended strings andunderlying resistance strips. This fingerboard is connected in circuitwith four individual tone generators and produces tones coveringslightly more than three octaves. It can be played alone or it can beplayed in conjunction with the neck fingerboard which covers fiveoctaves so that the two fingerboards together provide a range of fiveoctaves. Tone and volume controls are provided for the second section.

On the control panel are provided potentiometers of third and fourthsections which control aduio frequencies produced by two other separatetone generators. The frequency range controled by each potentiometerranges from 1 hertz to 2,640 hertz section three having an extra settingallowing it to reach 12,000 hertz. Individual tremolo circuits areprovided for the third and fourth sections. A vibrato bar for producingvibrato effects is provided for the first, third and fourth circuitsections. By rocking the vibrato bar, an associated potentiometer isvaried to cause an increase or decrease in pitch of tone or tones beingplayed. A remote power supply connected to the instrument provides D.C.voltage for operating all components.

The invention provides a musician with means for producing a wide rangeof electronically generated music. The musician can play individualpieces on the neck fingerboard or if desired, can accompany the piecesplayed on the neck fingerboard with tones generated by use of the bodyfingerboard or the potentiometer controls of the third and fourthsections. All four sections can be operated interchangeably to provideaccompaniment. This provides the musician with means for performing withseveral instrumental sections at once. For example, he may play a melodyon the neck fingerboard accompanied by a tonal or percussion rhythmsection and a bass section.

Tones produced by all sections may be continuously varied or sustained.The instrument thus provides a guitar-like instrument with features ofan electronic organ as well as features of a guitar.

Other and further features, objects and advantages of the invention willbecome apparent from the following detailed description taken togetherwith drawings, wherein:

FIG. 1 is a perspective view of an electronic musical instrumentembodying the invention.

FIG. 2 is an exploded fragmentary perspective view of parts of theinstrument showing how the neck is assembled with the body.

FIG. 3 is a perspective view of the neck per se in an inverted position,parts being broken away;

FIG. 3a is a cross-section along lines 3A-3A of FIG.

3. v FIG. 4 is a horizontal fragmentary, enlarged perspective view takenon line 4-4 of FIG. 1 showing the assembly of vibraor bar andpotentiometer.

FIG. 5 is a front view similar to part of FIG. 1 showing the controlpanel and body fingerboard on a scale enlarged over that of FIG. 1.

FIG. 5A discloses in detail the panel 12 of FIG. 5.

FIG. 6 is a front view of part of the neck with strings removed showingsimulated frets and musical tone locations.

FIG. 7 is a front view of the body fingerboard with strings removedshowing simulated frets and musical tone locations.

FIG. 8 is a further inlarged front view of the neck fingerboard andparts of the body, portions being broken away.

FIG. 9 is a magnified fragmentary sectional view taken on line 9-9 ofFIG. 8, parts being broken away.

FIG. 10 is a cross sectional view taken on line 10-10 of FIG. 9.

FIG. 11 is a magnified partial longitudinal sectional view of the bodyfingerboard taken on line ll--ll of FIG. 5, parts being broken away.

FIG. 12 is an exploded perspective view 'on a magnified scale showingone end of a resistor strip and electrical connector assembly.

FIG. 13 is a diagram showing the wiring hookup of the instrument with apower supply, audio amplifier and loudspeaker assembly.

FIG. 14 is a schematic diagram of the electronic system of theinstrument.

Referring first to FIG. 1, there is shown an electronic musicalinstrument embodying the invention. The instrument has a body formed bya rectangular circuit box 10 provided with an integral front panel 12and a removable back or bottom cover plate 13. On the panel are manuallyoperable controls 15 described in detail below. At one end of box issecured a generally U- shaped form 16 having contoured arms 18 and 19which serve for support of the instrument. The bight 20 of form 16 issecured to end wall 21 of box 10; see FIG. 2. Further forms 21,22secured to side walls 24, 24 of box 10 provide an hour-glass shape totheinstrument. A strap 26 is secured at opposite ends to form 21 and theend of one arm 19. This strap can be engaged around the shoulder of theplayer holding the instrument.

The instrument has an elongated neck formed by a flat wood or plasticbar 28. This bar terminates at its outer free end in spaced fingers 30.The inner end 28' of bar 28 is secured by screws 32 engaged in holes 34provided in a cutout or recess 36 formed in the bight 20 of form 16; seeFIG. 2. The bottom or rear side of bar 28 is formed with a groove 38through which extends a rod 40 threaded throughout or at least atopposite ends; see FIGS. 3 and 10. One end 40'(FIG. 3a) of rod 40 isengaged with a plate 42 set in grooves 44 extending laterally of one endof groove 38 and is held by a nut 45. The other end 40" of rod 40extends outwardly of the other end of groove 38 and is engaged in endwall 22 of box 10 and in a reinforcement plate 46 secured to end wall22; see FIG. 2. A nut 47 and washer 48 engage this end of rod 40. Thenut 47 can be tightened to tension bar 28 for straightening it or forholding it straight in the event it tends to bend forwardly toward thefront of the instrument. A cover plate or strip 49 is provided to covergroove 38 and rod 40 and is held by screws 49'; see FIG. 3. Neck bar 28fits snugly in recess 36 and is securely held there. If desired thejoint can further be reinforced by gluing the end 28' of bar 28 inrecess 36.

A vibrato control bar 50 has a handle 51 at its outer end which can bemanually grasped and moved up or down for controlling vibrato tones. Bar50 is L-shaped as best shown in FIGS. 1 and 4. Its shorter arm 52extends through a slot or hole 54 in panel 12 and is secured radially toa knob 55. Knob 55 is mounted at one end of a rotatable shaft 56 used toadjust variable resistor 58 mounted by a threaded sleeve 59 and nut 60on a support plate or bracket 62 on bottom plate 13 of the circuit box.A coil spring 64 is secured at opposite ends to the side of knob 55opposite from arm 52 to end wall 22' of the circuit box 10. Bar 50 canbe arranged to be rotated on arm 52 as an axis downwardly out of the wayof the player. i

The neck 25 has a neck fingerboard formed by six thin electricalresistance strips 72 bonded to insulative plastic strips 73. Thesestrips are in turn cemented to the front or upper side of neck bar 28;see FIGS. 6, 8, 9 and 10 and 12. The resistance strips are spaced apartlaterally and disposed parallel to each other in coplanar disposition onneck bar 28. Opposite ends of strip 72 are coated with films 74 ofsilver paint or other highly conductive liquid to serve as electricalterminals. Flathead bolts 76 extend through holes 78 in the films 74,strips 72 and 73 for engaging looped ends of insulated wires 79 and 79';see FIGS. 8, 9, 10 and 12. The bolts are secured by nuts 80 andlockwashers 82. The nuts 80 and lock-washers seat in recesses 83 formedin the neck under strips 73; see FIG. 9. Wires 79 extend along the topof bar 28 to circuit box 10 where they enter the circuit box through theholes 84 in panel 12; see FIGS. 5 and 8. Wires 79' are collected in acable 79" and run through groove 38 to the circuit box 10; see FIG. 10.

Registering holes 85 can be provided in end wall 22 and plate in thecircuit box for passing cable 79"; see FIG. 2. On neck bar 28 are screwsor pins 86 spaced apart longitudinally of the neck centrally thereonbetween adjacent resistor strips; see FIGS. 1, 6 and 8. These pins serveas simulated fret marks. The pins are spaced apa Ma l ns. ease s rrsspinsct flaqte-ffgif. A, B, C E, and the like ofa first musical octave,and notes G, A, B', and the like ofa second musical octave. These arefret locations familiar to guitar players so that the provision of thesefret markers on neck bar 28 facilitates playing of the instrument.

Playing of the instrument is made possible by electrically conductivewire strings 90 disposed parallel with the resistive strips andsupported above them by elevating bolts 92 near opposite ends of thestrings. The ends 90, 90" of the strings are engaged in passages 94formed in mounting bolts 96 through which the ends of the stringsextend. The string ends are soldered to lugs 97 by solder joints 98.String ends 90' are joined to a common wire 99 which enters circuit boxthrough hole 97; see FIGS. 5, 8 and 9. By pressing strings 90 againstresistive strips 72 at selected points along the neck fingerboard,different notes are sounded by the instrument. Some of these notes areindicated in FIG. 6. If a player runs his finger along any stringpressing each point of the string in succession against a strip 72,acontinuously varying tone will be produced by the instrument. The waythis is accomplished is explained further in connection with thecircuitry of the instrument shown in FIGS. 13 and 14.

A supplemental body fingerboard 100 is further provided on panel 12 ofthe circuit box 10. Here four parallel electrical resistance strips 102bonded to plastic strips 104 are disposed in laterally spaced coplanardisposition longitudinally of panel 12; see FIGS. 1, 5, 7, 8 and 11.Fret locations at notes G, A, B, C and the like are indicated by pins orscrew 106 located centrally of the fingerboard. One end of eachresistance strip has a silver film 108. Electrically conductive bolt 110has a flat head 111 overlaying this film. Attached to bolt 110 by nut112 and lockwasher 114 is a wire I16 extending through hole 117 in panel12 to the circuitry in circuit box 10; see FIG. 11.

Over each resistance strip is a flexible, electrically conductive wirestring 118 supported at opposite ends by elevating bolts 120,122.Opposite ends of the springs are clad in insulative tubing 124 engagedin passages 126 in the bolts. Ends 118' of the'strings are connected tocommon wire 128 which passes into the circuit box through a hole inpanel 12. Fingerboard 100 is played like fingerboard 70. Individual orcontinuously variable tones are producible.

The instrument is connected to a direct current power supply 130 andamplifier 132 via a cable 134 terminating in a plug 136 engaged in asocket 138 at one end of the circuit box 10; see FIGS. 1, 5 and 13.Amplifier 132 drives loudspeaker assembly 140 in conventional manner. Afour-channel mixer 133 of conventional type can be interposed betweenthe instrument and amplifier 132. A footswitch 142 is connected to thecircuit box and power supply via wires 143, 144. Operation of thisfootswitch is described in connection with the circuitry shown in FIG.14 to which reference is now made.

Circuit 150 has four sections S1-S4. Section S1 includes the neckfingerboard 70 comprising six strings 90 and resistance strips 72.Section S2 includes the body fingerboard 100 comprising four strings 118and resistance strips 102. Sections S3 and S4 include means forproducing tremolo and vibrato effects. Power is supplied to the circuitat 6 volts DC.

In Section S1 each of resistance strips 72 is connected in seriescircuit with a variable trimmer resistor 152, a transistor 154 and audiofrequency wave or tone generator 156. The output of tone generator 156is in series with base resistor 158, and base 159 of amplifyingtransistor 160. The outputs of all transistors 160 are applied tojunction point 164. The combined outputs are fed to the mixer-amplifier133, 132 via variable resistor 162 which serves as a volume control.Variable resistor 166 in series with capacitor 168 serves as a tonecontrol. Volume and tone controls 162, 166 are shown on panel 12 in FIG.5A over indicia reading VOL-S1 and TONE-S1. The tone generators 156 maybe conventional audio oscillators or signal generators variable inoutput frequency by change of input resistance and input current. Thevariable resistance is provided by each string 90 in association with aresistance strip 72. By pressing any string to contact a strip 72 at anypoint a greater or lesser amount of resistance of ths strip 72 is placedin series with the tone generator. The 6 volts power supply is appliedto each string 90 either continuously or momentarily. Momentaryapplication of dc. voltage is effected via pole 170 of LEAD PICK switch172. This pole is connected to all strings 90. Swtich 172 is a singlepole double throw pushbutton type of switch. When the switch button ispressed, the d.c. voltage is applied through fixed switch contact 188and pole 170 to all strings 90. The dc voltage can be appliedcontinuously to the strings via LEAD PICK BYPASS switch 176. This is atoggle switch which can be thrown to close pole 177 with switch contact178 for applying dc. voltage to the strings and cutting out or bypassingswitch 172.

Vibrato normal switch (VNl) 179 is connected to LEAD PICK switch 172 anda CHORD PICK switch 182. Pole 183 of switch 182 is connected in serieswith coil 184 of a six-pole chord control relay 185 for energizing thisrelay momentarily when the CHORD PICK switch is closed. Switch 182 is apushbutton switch. The locations of switches 172, 176, VN 179, VN 179',VN 179", on panel 12 are shown in FIG. 5A. Foot switch 142 is connectedbetween the 6 volts dc. power supply and relay coil 184 for energizingthis relay by pedal action of a player of the instrument. The movablecontacts 186 of relay 185 are all connected to pole 179 along with thepole 183 of switch 182 and contact 188 of switch 172. The fixed contacts190 of relay 185 are connected respectively to the resistance strips 72.A BASS-LEAD toggle switch 192 is connected between the power supply andcoil 194 of relay 196. This is a six-pole relay whose poles 198selectively connect either a bass control capacitor 197 or a lead(treble) control capacitor 199 between emitter 200 of transistor 154 andground. The location of BASS-LEAD switch 192 is shown on panel 12 inFIG. 5A.

In circuit section S2, each resistance strip 102 is connected in seriescircuit with trimmer resistor 202, transistor 204 and audio tonegenerator frequency wave or tone generator 206. The outputs of each ofthe four tone generators 206 is applied via load resistor 208 totransistor amplifier 210. The output of each amplifier 210 is appliedvia trimmer resistor 212 to junction point 215. Junction point 215 isconnected via volume control 216 to one of the mixer-amplifier inputs.The volume control is a variable resistor. Tone control 218 is avariable resistor which is in series with capacitor 220 and is connectedacross the volume control. The volume control 216 and tone control 218of section S2 are shown on panel 12 in FIG. 5A. The tone generators 206are conventional variable frequency audio oscillators. BASS-LEAD switch220 of section S2 is connected between the power supply and coil 221 ofrelay 225. This relay has four poles arranged to select either bass orlead capacitors 226, 227 for connection across the inputs of transistors204. Swtich 220 is shown on panel 12 in FIG. 5A.

In section S3, switch 179' is connected to contact 230 of EXTENDEDFREQUENCY switch 232. Switch 232 has a contact 233 connected to EXTENDEDFRE- QUENCY control 235. Switch 232 is connected in series with MAINFREQUENCY CONTROL 234, fixed resistor 236, and transistor 238 to audiofrequency wave or tone generator 240 which is audio oscillator having arange of l hertz to at least 12,000 hertz. The output of the tonegenerator 240 is connected to transistor amplifier 242. The output ofthis amplifier is applied via volume control 244 to a tremolo circuit245 described below. The output of the tremolo circuit is applied to oneinput of the mixeramplifier 133, 132. Tone control 246 in series withcapacitor 248 is connected across the volume control. Frequency selectorswitches 251, 252 selectively connect capacitors of different valuesacross the input of transistor 238. The locations of switches 232, 251,252, and controls 234 235, 244, 246 on panel 12 are shown in FIG. 5A.Control 235 is mounted at the end of circut box 10.

In section S4, variable resistor 58 is adjusted by vibrato bar 50. Thisresistor is connected to contact 260" of VIBRATO NORMAL switch 179'. VNswitch 179" is connected to lEXTENDED FREQUENCY switch 258. In normalposition of the VN switches, the vibrato bar is bypassed. When each ofswitches 179, 179' and 179" close with contacts 260, 260 and 260", theoperation of the vibrato bar is possible since resistor 58 is theneffectively connected in circuit with the tone generators of sectionsS1, S3 and S4. MAIN FRE- QUENCY CONTROL switch 262 of section S4 iscorinected in series with switch 258, transistor 264 and sudio frequencywave or a tone generator 266. The tone generator has a range of l hertzto at least 2,640 hertz. It is connected to transistor amplifier 268.The output of amplifier 268 is applied via a trimmer resistor 270 andvolume control 272 to tremolo circuit 245'. A tone control 273 in serieswith capacitor 274 is connected across the volume control. Frequencyselector switch 277 and capacitors 279 are connected between the inputof transistor 264 and ground. The switches and controls 258, 262, 273and 272, 277 of section S4 are shown on panel 12 in FIG. 5A.

The tremolo control circuits 245 and 245 are identical. Each circuitincludes a dc voltage source 280 connected via a switch 285 totransistor 286. Variable resistor 288 connected across the transistor ina resistance-capacitance circuit serves as a SPEED CON- TROL. The audiofrequency output of sections S3 or S4 is applied to transistor 290 via aswitch 292 when thrown to contact 294. Transistor 286 drives transistor290 via INTENSITY control 295. The tremolo circuits 245 and 245' haveseparate SPEED and INTENSITY controls 288, 295 and 288 and 295' in thetwo sections S3, S4; see FIG. 5A. Joint switches 285, 292, and 285 and292 are also shown in FIG. 5A. The output of transistor 290 is appliedto one of the mixer-amplifier inputs.

In operation of the instrument including circuit 1.50, any one of thesix tone generators oscillates instantly when any string 90 contacts aresistance strip 72 at any point if d.c. voltage is applied to thepressed string. Voltage is applied to the strings momentarily if theLEAD PICK switch 172 is pressed or voltage is applied continuously ifthe LEAD PICK BYPASS switch 176 is closed. The desired bass or lead(treble) range is selected by operation of the BASS-LEAD switch 192which energizes relay 196. Notes are picked operating the LEAD PICKswitch 172 to control the interval of time voltage is applied to thestrings selectively pressed. A plurality of tones constituting a chordare picked by momentary operation of the CHORD PICK switch 182 while twoor more strings are pressed against the resistance strips. The chord canbe sustained by holding switch 182 depressed. An open string chord ofall six strings can be produced by pressing the CHORD PICK switch 182without pressing any string. The variable frequency tone generators haverelative frequencies corresponding to note intervals of the temperedscale as used on a conventional guitar. Thus indicated in FIG. 14, fullopen string notes correspond to standard low E, A, D, G, B and highguitar E strings. When either PICK switch 172 or 182 is closed, pressingany string against a resistance strip has the effect of reducingresistance in the input to transistor 1154 resulting in a rise infrequency increase the pitch of tone produced. During stringpicking twohands are used, one at strings 90 and the other at the desired PICKswitch. If one hand playing of individual notes is desired, LEAD PICKBYPASS switch 176 will be closed to apply dc. voltage to all stringscontinuously. One hand playing of chords can be done by closing the footswitch 142 which energizes the relay 184 continuously to apply voltageto all resistance strips. Barred chords can be produced innormal mannerwithout any need to use the CHORD PICK switch.

By operating the VIBRATO NORMAL switches 179, 179 and 179", and vibratobar 50, notes or chords can be modulated toincrease or decrease slightlyin pitch. Moving the bar in one direction the pitch is increased andmoving the bar in opposite direction, the pitch is decreased. Normallythe potentiometer or resistor 58 has certain resistance when bar 50 isat rest in neutral position. Moving the vibrato bar up or down variesthe resistance applied in circuit with the resitance strips to vary thefrequencies of the tone generators activated by pressing the stringsagainst resistance strips.

The combined outputs of the tone generators after amplification bytransistors 160 all controlled in volume by VOLUME control 162. The tonecontrol 160 serves as a treble frequency bypass to vary the outputs ofall tone generators 156 simultaneously. The outputs of section S] areapplied to audio amplifier 132 and loudspeakers 140 via four-channelmixer circuit 132. This mixer can be operated in known manner to producevarious special sound effects.

The neck fingerboard provides for five octaves of notes ranging from lowbass E to treble ranging from low bass E to treble E; tuning of the Estring of S1 and S2 is indicated in FIGS. 6 and 7. The resistancelengths of strips 72 are selected and calculated so that the normalstring tuning of the neck fingerboard at their highest points is asfollows corresponding to the six bass guitar or the six string standardguitar:

Bass Lead Low E 164.8 hz 329.6 hz A 220 hz 440 hz D 293.6 hZ 587.3 hz

G 391.9 hz 783.9 M

B 493.8 hz 987.7 hz High E 659.2 hz 1318.5 hz

Bass Lead Low E 82.4 hz 164.8 hz A hz 220 hz D 146.8 hz 293.6 hz

G 195.9 hz 391.9 hz

It will be noted that some overlap is provided at the high end of thebass range and the low end of the lead range. Chords are produced byfinger pressing desired strings.

In sections S3 and S4, both tone generators are con stantly energizedand oscillating. They are silenced by turning down the volume controls244 and 272. The MAIN FREQUENCY controls 234 and 262 each covers a rangeof three octaves. By use of the FRE- QUENCY SELECTOR switches 251, 2 52and 277 a desired tonal range can be produced as follows:

Low 5 to 40 hz Mid-range 40 to 330 hz High .330 to 2640 hz Ultra-high1500 to 12,000 hz section three only.

Sections S3 and S4 can be used in conjunction with .vibrato bar 50 byoperating the VIBRATO NORMAL switch 199' and 179" either separately orsimulta neously with the neck fingerboard 70.

By operating the EXTENDED FREQUENCY switches 232 and 258 either tonegenerator 240 or 266 can be used in conjunction with the EXTENDED FRE-QUENCY control 235 to further lower the frequency range of the tonegenerators. When switch 252 in section S3 is at ULTRA-HIGH selection,control 235 can be set at a high resistance point. This applies highresistance to transistor 238 in section S3 and causes a white noise,volcano or avalanche sound efffect which can be varied by tone control246 for further enhancement of a deep rumbling noise effect. If theresistance of extended frequency control 235 is increased still further,it has the effect that if various tones on the remaining sections S1, S2and S4 are produced, section S3 will accompany these tones with anadditional tone one octave lower in frequency than the original tone s,causing a pleasing musical effect found on conventional 12-stringguitars. If the tones produced by sections S1, S2, or S4 are silenced byturning down volume controls 162, 216, or 272, respectively, only theaccompanying tones are heard. This effectively lowers the frequencyrange of tones produced by either section S1 or S2 to as low as 20 hz,even though this lower frequency range is an output of tone generator240 in section S3. These lower tones can be further effected by the tonecontrol 246 of section S3. The player can produce various frequencymodulation effects through the combined use of all three frequencycontrols 234, 235 and 262. As an example an oscillating siren effect canbe produced. The tremolo circuits 245 and 245 provide amplitudemodulation of the tones generated by generators 240 and 266respectively. They are actuated by operating the tremolo switches 285,292 and 28S and 292. Speed and intensity controls 288, 288' and 295, 295permit adjustment of tremolo effects.

On the panel 12 of FIG. A, except for lead pick switch 172 and chordpick switch 182 which are normally pushbutton switches, remaining otherswitches are toggle type switches.

Since the contacts of the strings and resistance strips are continuouslyvariable from end to end of the strings, an umlimited variety of musicalscales and tonal fluidity is attainable. The fret markings 86 and 106locate exact points where specified notes can be produced.

The instrument can be regarded as covering five continuous octaves whenfingerboards 70 and 100 are played together. In addition threeadditional octaves are covered by each of sections S3 and S4 when allrange selections are used.

In its preferred form the neck fingerboard is eighteen inches long andthe body fingerboard is nine inches long as indicated in FIGS. 6 and 7.However other lengths to suit the needs of players can be used.

A prior art U.S. Pat. No. 3,223,771 covers a musical devicesuperficially similar to the above-described invention; however, thereare major significant differences such as the patented device: does nothave nor disclose a combination of several electrical circuits ofrespectively several musical sections; does not disclose nor suggestresistor strips", does not disclose nor suggest a plurality of stringseach with its own generator circuit, i.e. the patent uses one generatorfor a plurality of strings for a single generator thereby preventingplaying concurrently on more than one string; the patent cumbersomelyincludes the amplifier and speaker built-in; and the like.

While a preferred embodiment of the invention has been described, itwill be apparent that many modifications and variations are possiblewithout departing from the spirit of the invention.

What is claimed is:

1. An electronic musical instrument comprising a central, flat hollowbody; contoured forms extending outwardly of sides and one end of thebody for supporting the same; a neck extending outwardly of one of theforms at said one end of the central body; a first section including afirst fingerboard on said neck comprising a plurality of flat, laterallyspaced coplanar electrical resistance strips, and a plurality ofelectrically conductive wire strings suspended over said stripsrespectively; and electronic circuitry in said central body including aplurality of audio-frequency electronic wave tone generatorselectrically connected in circuit with said strings and strips forproducing different tones when said strings are selectively pressedagainst the strips, said tones depending in pitch on the particularstring pressed and the particular point at which the pressed stringcontacts an underlaying resistance strip; said central body has acontrol panel, and tone and volume controls mounted on said panel andconnected in circuit with said generators for respectively adjustingtone and volume of pitch produced by operation of said fingerboard; andfurther comprising a plurality of potentiometers on said control panel;said electronic circuitry further comprising a plurality of furtheraudio frequency wave generators connected in circuit with saidpotentiometers respectively for generating tones extending in frequencyover a prescribed frequency range for accompanying tones produced byoperation of the fingerboard; further comprising third section tremologenerating means connected in circuit with said further wave generatorsfor controllably producing tremolo effects when said further generatorsare active; further comprising a fourth section including a vibrato barand another potentiometer in said central body connected in circuit withthe first named wave generators and said further wave generators forvarying pitch of tones produced thereby and said vibrato bar movablymounted on said control panel and connected to said other potentiometerfor producing vibrato effects when said vibrato bar is moved while thefirst named and other wave generators are producing tones of selectedpitches.

2. An electronic musical instrument as defined in claim 1, wherein saidfingerboard has spaced markers thereon designating predetermined musicalintervals corresponding to those of a conventional stringed guitar.

3. An electronic musical instrument of claim 1, in which in seriescircuit with said third section tremolo generator means is athird-section volume control means receivable of output of said thirdsection tremolo generator means, and in which a third-section tonecontrol is connected across said volume control and in which in saidfourth section connected in series circuit with said vibrato bar is aswitch, a transistor and said tone generator receivable of signalsthrough said switch through said transistor, a trimmer resistor fed bythe fourth section generator, and a fourth-section volume control fed bysaid trimmer resistor, said fourth-section volume control beingconnected to feed its output to said third section tremolo generator.

4. An electronic musical instrument comprising a central, flat hollowbody; contoured forms extending outwardly of sides and one end of thebody for supporting the same; a neck extending outwardly of one of theforms at said one end of the central body; a first fingerboard on saidneck comprising a plurality of flat, laterally spaced coplanarelectrical resistance strips, and a plurality of electrically conductivewire strings suspended over said strips respectively; and electroniccircuitry in said central body including a plurality of audio frequencyelectronic wave generators electrically connected in circuit with saidstrings and strips for producing different tones when said strings bothseparately and jointly are selectively pressed against the strips, saidtones depending in pitch on the particular string pressed and theparticular point at which the pressed string contacts an underlayingresistance strip; said central body has a control panel, and tone andvolume controls mounted on said panel and connected in circuit with saidgenerators for respectively adjusting tone and volume of pitch producedby operation of said fingerboard; a second fingerboard on said controlpanel comprising a plurality of other flat, laterally spaced coplanarelectrically conductive resistance strips, and a plurality of otherelectrically conductive wire strings suspended over said other stripsrespectively; said electronic circuitry further including a plurality ofother audio frequency waves generators electrically connected in circuitwith said other strips and strings for producing still other tones whensaid other strings are selectively pressedagainst the other strips, saidother tones depending in pitch on the particular other string of thesecond fingerboard pressed and the particular point at which the pressedother string contacts an underlaying resistance strip, said first andsecond fingerboards being operable for producing all of said tonessimultaneously.

5. An electronic musical instrument as defined in claim 4, furthercomprising other tone and volume controls mounted on said panel andconnected in circuit with said other generators for respectivelyadjusting tone and volume of pitches produced by operation of saidsecond fingerboard.

6. An electronic musical instrument as defined in claim 4, furthercomprising a plurality of potentiometers on said control panel; saidelectronic circuitry further comprising a plurality of further audiofrequency wave generators connected in circuit with said potentiometersrespectively for generating tones extending in frequency over aprescribed frequency range for accompanying tones produced by operationof the fingerboard.

7. An electronic musical instrument as defined in claim 6, furthercomprising tremolo generating means connected in circuit with saidfurther wave generators for controllably producing tremolo effects whensaid further generators are active.

8. An electronic musical instrument as defined in claim 5, furthercomprising a plurality of potentiometers on said control panel; saidelectronic circuitry further comprising a plurality of further audiofrequency wave generators connected in circuit with said potentiometersrespectively for generating further tones extending in frequency over aprescribed frequency range for accompanying tones produced by operationof the first and second fingerboards.

9. An electronic musical instrument as defined in claim 6, furthercomprising another potentiometer in said central body connected incircuit with the first named wave generators and said further wavegenerators for varying pitch of tones produced thereby; and a vibratobar movably mounted on said control panel and connected to said otherpotentiometer for producing vibrato effects when said vibrato bar ismoved while the first named and other wave generators are producingtones of selected pitches.

10. An electronic musical instrument as defined in claim 4, wherein saidcircuitry further comprises switch means connected in circuit with thefirst named and other wave generators for controlling time intervalsduring which said fingerboards are operable to produce tones.

11. An electronic musical instrument as defined in claim 4, wherein saidcircuitry further comprises switch means for shifting the frequencyranges of tones produced by operation of the fingerboards.

1. An electronic musical instrument comprising a central, flat hollowbody; contoured forms extending outwardly of sides and one end of thebody for supporting the same; a neck extending outwardly of one of theforms at said one end of the central body; a first section including afirst fingerboard on said neck comprising a plurality of flat, laterallyspaced coplanar electrical resistance strips, and a plurality ofelectrically conductive wire strings suspended over said stripsrespectively; and electronic circuitry in said central body including aplurality of audio-frequency electronic wave tone generatorselectrically connected in circuit with said strings and strips forproducing different tones when said strings are selectively pressedagainst the strips, said tones depending in pitch on the particularstring pressed and the particular point at which the pressed stringcontacts an underlaying resistance strip; said central body has acontrol panel, and tone and volume controls mounted on said panel andconnected in circuit with said generators for respectively adjustingtone and volume of pitch produced by operation of said fingerboard; andfurther comprising a plurality of potentiometers on said control panel;said electronic circuitry further comprising a plurality of furtheraudio frequency wave generators connected in circuit with saidpotentiometers respectively for generating tones extending in frequencyover a prescribed frequency range for accompanying tones produced byoperation of the fingerboard; further comprising third section tremologenerating means connected in circuit with said further wave generatorsfor controllably producing tremolo effects when said further generatorsare active; further comprising a fourth section including a vibrato barand another potentiometer in said central body connected in circuit withthe first named wave generators and said further wave generators forvarying pitch of tones produced thereby and said vibrato bar movablymounted on said control panel and connected to said other potentiometerfor producing vibrato effects when said vibrato bar is moved while thefirst named and other wave generators are producing tones of selectedpitches.
 2. An electronic musical instrument as defined in claim 1,wherein said fingerboard has spaced markers thereon designatingpredetermined musical intervals corresponding to those of a conventionalstringed guitar.
 3. An electronic musical instrument of claim 1, inwhich in series circuit with said third section tremolo generator meansis a third-section volume control means receivable of output of saidthird section tremolo generator means, and in which a third-section tonecontrol is connected across said volume control and in which in saidfourth section connected in series circuit with said vibrato bar is aswitch, a transistor and said tone generator receivable of signalsthrough said switch through said transistor, a trimmer resistor fed bythe fourth section generator, and a fourth-section volume control fed bysaid trimmer resistor, said fourth-section volume control beingconnected to feed its output to said third section tremolo generator. 4.An electronic musical instrument comprising a central, flat hollow body;contoured forms extending outwardly of sides and one end of the body forsupporting the same; a neck extending outwardly of one of the forms atsaid one end of the central body; a first fingerboard on said neckcomprising a plurality of flat, laterally spaced coplanar electricalresistance strips, and a plurality of electrically conductive wirestrings suspended over said strips respectively; and electroniccircuitry in said central body including a plurality of audio frequencyelectronic wave generators electrically connected in circuit with saidstrings and strips for producing different tones when said strings bothseparately and jointly are selectively pressed against the strips, saidtones depending in pitch on the particular string pressed and theparticular point at which the pressed string contacts an underlayingresistance strip; said central body has a control panel, and tone andvolume controls mounted on said panel and connected in circuit with saidgenerators for respectively adjusting tone and volume of pitch producedby operation of said fingerboard; a second fingerboard on said controlpanel comprising a plurality of other flat, laterally spaced coplanarelectrically conductive resistance strips, and a plurality of otherelectrically conductive wire strings suspended over said other stripsrespectively; said electronic circuitry further including a plurality ofother audio frequency waves generators electrically connected in circuitwith said other strips and strings for producing still other tones whensaid other strings are selectively pressed against the other strips,said other tones depending in pitch on the particular other string ofthe second fingerboard pressed and the particular point at which thepressed other string contacts an underlaying resistance strip, saidfirst and second fingerboards being operable for producing all of saidtones simultaneously.
 5. An electronic musical instrument as defined inclaim 4, further comprising other tone and volume controls mounted onsaid panel and connected in circuit with said other generators forrespectively adjusting tone and volume of pitches produced by operationof said second fingerboard.
 6. An electronic musical instrument asdefined in claim 4, further comprising a plurality of potentiometers onsaid control panel; said electronic circuitry further comprising aplurality of further audio frequency wave generators connected incircuit with said potentiometers respectively for generating tonesextending in frequency over a prescribed frequency range foraccompanying tones produced by operation of the fingerboard.
 7. Anelectronic musical instrument as defined in claim 6, further comprisingtremolo generating means connected in circuit with said further wavegenerators for controllably producing tremolo effects when said furthergenerators are active.
 8. An electronic musical instrument as defined inclaim 5, further comprising a plurality of potentiometers on saidcontrol panel; said electronic circuitry further comprising a pluralityof further audio frequency wave generators connected in circuit withsaid potentiometers respectively for generating further tones extendingin frequency over a prescribed frequency range for accompanying tonesproduced by operation of the first and second fingerboards.
 9. Anelectronic musical instrument as defined in claim 6, further comprisinganother potentiometer in said central body connected in circuit with thefirst named wave generators and said further wave generators for varyingpitch of tones produced thereby; and a vibrato bar movably mounted onsaid control panel and connected to said other potentiometer forproducing vibrato effects when said vibrato bar is moved while the firstnamed and other wave generators are producing tones of selected pitches.10. An electronic musical instrument as defined in claim 4, wherein saidcircuitry further comprises switch means connected in circuit with thefirst named and other wave generators for controlling time intervalsduring which said fingerboards are operable to produce tones.
 11. Anelectronic musical instrument as defined in claim 4, wherein saidcircuitry further compriSes switch means for shifting the frequencyranges of tones produced by operation of the fingerboards.